Trailer Brakes Lock Up as Soon as Trailer Is Connected to Truck
Question:
I have a brand new dump trailer and when I plug my trailer cord into my truck the brakes set, the truck has been checked by three people, the wireing on the truck is right but the brakes still lock up?
asked by: Bob B
Expert Reply:
If the trailer brakes lock up as soon as you plug in the trailer to the truck then there is either a short circuit or there is corrosion build up in the vehicle or trailer side connectors. It could also mean that either the truck or the trailer is pinned out differently. This is a typical occurrence on a 6-Way round pin connector since the center pin will either be 12 volt power or brake output.
Make sure that both connectors are clean and free of corrosion inside and out. On a 7-Way blade style connector, the brake output pin on the truck side is in the 5 oclock position and on the trailer side it is in the 7 oclock position. Just make sure that is where the brake circuits are on the truck and trailer connectors to eliminate that as a possibility. If something needs to be moved just access the back of the connector and move the wires as needed. You can follow the diagrams in the help article I have linked.
If you believe that the problem is with the brake controller then you can test it too. I have included a couple of links that show how you can test and troubleshoot brake controllers.
